merge glu 9.0.2.

initial import of glu-9.0.2

Changing GLU_TESS_MAX_COORD to DBL_MAX causes internal constants derived
from GLU_TESS_MAX_COORD used in libtess to be +/-inf, leading to
logic errors. See
http://mail-index.netbsd.org/tech-x11/2016/05/25/msg001733.html
and
http://willkamp.com/opencpn/flyspray/index.php?do=details&task_id=2076
for details.
Change back GLU_TESS_MAX_COORD to its upstream value if it fits
in a double, or 1e15 if DBL_MAX_10_EXP is not large enough
(fix proposed by christos@)

Fixes segfaults and crashing in applications that use libGLU.

This commit was approved by wiz@

use DBL_MAX instead of 1.0e150...

initial import of glu-9.0.0